1. Field of the Invention
The present invention relates to the field of telecommunications. In particular, the present invention relates to emergency operation of a mobile network.
2. Background of the Invention
Providing for reliable means of communication between those in distress and authorities is one of the most crucial aspects of managing an emergency situation. Systems and devices for wirelessly sending out a distress signal are known in the art. For example, Personal Locator Beacons (PLBs) can send out a distress signal, possibly including GPS information, for reception by specialized satellites, which forward the signal to rescue authorities. Typically such a beacon is actuated manually by a person in distress. Such a system has several drawbacks including the time it takes for the specialized satellites to detect the distress signal and the need for specialized hardware in the form of a PLB for each user. Further, such a system does not provide any way for the person in distress to indicate to what extent they are in danger.
More recently, such functionality has been integrated into mobile phones and mobile phone networks, eliminating the need for specialized hardware to send the distress signal. There are systems whereby users of mobile devices can notify a communications server that they are currently in distress or, for a specified time period, could possibly be in distress. User information, including location information, can then be forwarded to security personnel for action.
Such systems have drawbacks in some emergency situations, particularly large-scale disasters, such as earthquakes, hurricanes, tornadoes, floods, fires, etc. In such an event, the usual mobile network may be no longer working. Although such a system allows individual users to disclose information about their predicament, it does not provide any means for efficiently organizing all this incoming information and disseminating it on a wide scale to rescuers. Furthermore, people in distress may be injured, unconscious, or otherwise not able to initiate a distress call. For example, in the event of a missing child, the child may not know that they should get in touch with the police. In some cases, authorities may know the identity of an incapacitated person but have no means of tracking or otherwise getting in touch with them—for example, in the event of a hostage taking. A purely user-initiated emergency distress system does not allow for authorities to initiate the emergency distress features of mobile network devices, which may be necessary in events, such as the release of a toxic gas, where it may not be immediately apparent that a disaster has happened at all.
Especially in a large-scale disaster situation, it is very easy for communications networks to be overwhelmed. Frightened users may swamp a 911 network with calls. The study “Emergency Communication and Information Issues in Terrorist Events Involving Radioactive Materials”, by Steven Becker, identified a concern that the telephone system, and especially the 911 system, would be overwhelmed in the event of a terrorist attack involving radioactive materials. This is one of the chief concerns emergency response professionals have about communications during such an attack. Some survivors of the August 2007 Interstate 35W bridge collapse in Minneapolis were unable to inform their families of their whereabouts, due to a surge in traffic on mobile phone networks. A purely user-initiated emergency distress system is thus vulnerable to breakdowns or delays in critical communications because there is no way for authorities to manage bandwidth usage. Telephone systems, including cellular telephone systems, typically give 911 traffic priority, but as indicated, in a large scale disaster the 911 system is likely to be overwhelmed.
Battery usage by mobile devices is another critical issue not addressed by current emergency distress systems. Any mobile device used for emergency communication only works as long as its batteries do. This is especially critical during large-scale disasters because users may be unable to recharge their devices, such as in a power outage. However, battery usage is often an issue during protracted personal emergencies as well. In a life-or-death situation, it is crucial that mobile devices used for emergency communication last as long as they possibly can.
Finally, current systems that use mobile devices for emergency communications do not provide for the organized dissemination of emergency information to all users of a mobile network by authorities. Particular communities, such as a university campus, have instituted emergency notification systems, but typically require users of the system to sign up for the service. People who have not signed up for the service do not receive the emergency notifications. Thus, in such a system, many people who are affected by an emergency do not receive the crucial emergency notifications. Some people who do receive the emergency notifications, such as people who are out of town, receive emergency notifications for emergencies that do not affect them. Such a system does not provide a way to broadcast an emergency notification to all users of a mobile network in a certain vicinity affected by an emergency, whether they have registered for such notifications or not.
Thus, there is a clear need for a system of operation of mobile networks and mobile network devices that is optimized for the conditions that characterize large-scale disasters. Such a system including features to conserve the battery of mobile devices would also be beneficial for maintaining communications between users and authorities during protracted personal emergencies.